- In Fractured, a Mass Effect/Star Wars crossover, the Trans-Galactic Republic's large Star Dreadnaughts are viewed this way due to using huge amounts of energy to operate, leaving them short-ranged and requiring massive supply lines.
- In TheMasksWeWear, both Zuko and Azula learn how to use their firebending to fly by using controlled jets of flame.
- In the Uplifted series, The Tiger tank prototype, as Hoch and Hanala find out when trying to take one deep behind enemy lines in Libya. It's clunky, over engineered, and unreliable in the conditions they face.
- In Aeon Natum Engel and Aeon Entelechy Evangelion the Military views the Evangelions as unnecessary large Engel-prototype relics from the past. In the latter this view is somewhat extended to the conventional mecha, at least by the tank crews.
- BlackMegaGargomon from the Tamers Forever Series has an unbelievably powerful technique known as the Black Moon Flare, which causes unfathomable amounts of devastation within a vast radius. Unfortuneatly, the technique happens to be a little too powerful, and D.C is only ever able to manage one use of it. And that ends up being a Worf Barrage
- In Calvin At Camp, Calvin, Jason, and Marcus try to attack Kevin with medieval weapons, but find out the hard way that although the weapons look cool, they are impossible to lift.
- In Shadow Snark, the titular characters wings are made of solid iron, which though badass doesn't give him the ability to fly. A very crippling handicap for a pegasus.
- In Princess Of The Blacks, Jennifer (A Gender Flip of Harry) uses a form of invisibility that's undetectable to Moody's magic eye. However, since it works by bending light away from a person, they're likewise blind for its duration. The only reason Jennifer uses it is because she's already blind (though on a potion regimen to regain her sight).
- In the My Little Pony: Friendship Is Magic fanfic, The Dusk Guard: Rise resident Wrench Wench Sky Bolt has several ideas for things like fast and powerful airships and protective armor, but acknowledges that they are too expensive and material-heavy for mass production and general use. For a six-pony Elite Army such as the Dusk Guard however, they're absolutely perfect. In fact, it is the ability to pursue these ideas that Steel Song uses to entice Sky Bolt into the unit.
- In Bleach/Naruto crossover True Warriors Never Die, Naruto is the jinchuuriki of the Juubi which (in addition to having 2000 years to hone his skills) gives him destructive power comparable to Yamamato. The downside is that he has to fight the Juubi roughly every 1000 years to insure it doesn't try to destroy the world again. As he recently found out, the more he uses its power, the faster the Juubi recovers. In fact, despite using his jinchuuriki mode only a few times, the Juubi is already stirring, 900 years early.
- The Galaxy Crusher in Sonic X: Dark Chaos is a star-sized Demon superweapon capable of erasing an entire galaxy with a single shot and has the defensive firepower of over half the entire Demon Imperial Navy. However, the sheer collateral damage it causes and its mind-boggling logistic requirements (and the threat of it being turned against its creators) led Maledict to deactivate it after it was only used once. The entire Demon military itself can also pretty much described as Awesome, but Impractical, focusing on enormously large and powerful battle machines that are expensive to operate and replace.
- The killing curse and other magical means of murder are this in Broken Souls. They're guaranteed to get the job done, but are often seen by others in the area because they're so flashy. This is why a group of Soviet assassins were able to get away with so many hits; they would apparate near the victim, slash their throat, and leave without any flashy spells.
- In Getting Too Old For This Harry Potter can modify firearms to be so powerful, they can be fired at a ship in orbit and still "ruin someone's day". However, he's the only person in the galaxy who can make said modifications. And it takes him at least thirty hours for a single gun, and if he makes a single mistake it could result in a nuclear explosion. Thankfully, those are the only drawbacks; once a gun is completed, it's just as safe and reliable as any gun like it.
- In George Orwell's Nineteen Eighty-Four, it's implied that the Forever War going own between the three superstates is a sham, and all the weapons they build are deliberately designed to be as flashy and intimidating as possible and waste resources as much as possible. They're not actually built for fighting and winning wars. This really bites them in the ass in America's Stepbrother, America's Enemy V2.0, where the real life United States of 2012 is planted into the world of 1984 by spatial anomaly and Oceania decides to invade it. Up against far more advanced and practical American weaponry, the Oceanian military completely gets its ass kicked.
- In Supernova Nami learns to use Soru as early as the fight with Captain Kuro. Unfortunately she's isn't in good enough shape to use it properly so each use leaves her legs in agony.
- Johnny and Yosaku's ultimate techniques during the Alabasta arc in Shinobi Of The High Seas leaves their legs and hands useless respectively.
Awesome But Impractical / Fan Fiction
"A flashy feature that has limited usability for victory."